It is none of youtube's business whether I fell asleep or not. Data is mostly unlimited these days so why are they all up in my business? I checked auto-play for a reason!

You could have fallen asleep, overdosed on drugs, be tied up during an armed robbery, be dead etc…
In any of those scenarios your video is still playing but you are NOT still watching.
That's all the app wants to know.
My password is password.